Cataracts is the clouding in the clarity of natural lens of the eye. It is a kind of fogging of the eye lens leading to degradation of the visual quality. The eye lens is situated in the front of the eye and its composition is naturally clear. Its main function is to focus light on to the retina. However, when cataracts develops, the lens starts becoming opaque and only partial light gets transmitted through it, leading to impaired vision. In most cases, cataracts affects only a small part of the lens and in most cases the vision is not greatly affected. However, if a larger portion of the lens gets affected, then it becomes imperative to remove the cataract.
There are numerous misconceptions associated with cataracts.
- It is not caused because of the overuse of the eye.
- It can affect both eyes at the same time.
- They do not appear instantly, but gradually develop over many years. Moreover they are not at all related to cancer.
- Cataracts are treatable, so, patients with severe cataracts have treatment options available.
Main Types of Cataracts
Cataracts are of many types. The main cause of cataract is the variation in the chemical composition in the lens, which causes loss of transparency. These variations can be attributed to aging, diseases, injuries or hereditary reasons.
In senile cataract, normal aging can cause hardening of the lens and eventually cloudy vision. This is the most common type of cataract. Congenital Cataracts are found in children and this can be caused due to either hereditary reasons or birth related infections. Eye injuries are another major reason for developing cataracts. A cut, hard blow, heat or chemical burn can result in traumatic cataract. Some kind of infections and diseases like diabetes can cause secondary cataract.
The symptoms of cataract can include blurred vision, high sensitivity to light, and difficulty in perception of colors, increased myopia, and frequent change of eyeglass number and in some cases double vision. Some patients experience 'second sight', a phenomenon in which there is an improvement in their reading vision due to cataract swelling. Since major Cataracts are of senile nature and develop gradually over a period of time, most patients are unable to detect the condition unless the situation becomes severe.
Eye specialists recommend cataracts surgery only when there are higher chances of vision losses. Three types of surgeries are most commonly performed in cataract for vision restoration. These surgeries are Extracapsular Surgery and Photoemulsification. The first surgery involves the removal of the lens, but the posterior capsule found in the rear of the lens is kept intact. While in Photoemulsificatiion, the lens is softened using sound waves and taken out using a needle. But the posterior capsule is again kept intact. Another type of surgery called Intracapsular Surgery, which is not commonly used, consists of complete removal of the lens and the capsule. The lens is then replaced with an intraocular lens. But in cases where it is not possible due to some diseases, then a soft contact lens is placed in place of the natural lens. Normally cataracts affect both eyes together, but it is recommended not to perform surgery in both the eyes at the same time. Doctors usually wait after a surgery on a single eye to study the results and risks.